<template>
  <!-- 封装的轮播图组件 -->
  <div class="box" style="height: 500px">
    <div class="xtx-slider">
      <ul
        class="slider-body"
        @mouseenter="mouserenter"
        @mouseleave="mouseleave"
      >
        <li
          class="slider-item"
          v-for="(item, i) in sliders"
          :key="i.id"
          :class="{ fade: index === i }"
        >
          <img :src="item.imgUrl" alt="" />
        </li>
      </ul>
      <!-- 圆点 -->
      <div class="slider-indicator">
        <span
          :class="{ active: index === i }"
          v-for="(item, i) in sliders"
          :key="i"
          @click="index = i"
        ></span>
      </div>
    </div>
  </div>
</template>

<script>
import { onMounted, ref, onUnmounted } from 'vue'
export default {
  name: 'XtxSlider',
  props: {
    sliders: {
      type: Array,
      default: () => { return [] }
    },
    autopaly: {
      type: Boolean,
      default: true
    }
  },
  setup (props) {
    const index = ref(0)
    const timer = ref(null)
    // 鼠标移入
    function mouserenter () {
      clearInterval(timer.value)
    }
    // 鼠标移出
    function mouseleave () {
      init()
    }
    // 封装函数轮播
    function init () {
      if (!props.autopaly) return false
      timer.value = setInterval(() => {
        index.value += 1
        if (index.value === props.sliders.length) {
          index.value = 0
        }
      }, 1000)
    }
    // 页面构建完就开始轮播
    onMounted(() => {
      init()
    })
    // 清除定时器
    onUnmounted(() => {
      clearInterval(timer.value)
    })
    return { index, mouserenter, mouseleave }
  }
}
</script>

<style scoped lang='less'>
.xtx-slider {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .slider {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .slider-btn {
      opacity: 1;
    }
  }
}
</style>
